Actually, there are very FEW notable Jedi who ever fell to the Darkside and then went back to the light, and even fewer who were raised as Sith and later became Jedi, and this involves the ENTIRE star-wars universe.

And even then, it literally barely ever happened in the centered (movies) universe, because one of the principles of the Jedi, taught by Mace Windu, Obi-Wan, and especially Yoda himself was that once you became a Dark Jedi you could never again be totally "light-sided" or good.

You mix a lot things up. At first Wando was only a Padawan, he never fought on the dark side.
I guess you mean Windu who also never worked for the dark side, only his light sabber style Vaapad used force near of the dark one.

Neither Obi Wan nor Yoda where anywhere on the dark side, also both stated something like: 'once you go black you never change back!'

There are only a concept arts of Obi wan as a sith lord for SW Battlefront 3, which was never released.